In motion picture, video and television production, smooth camera movement is essential. To this end, the camera is often supported on a camera dolly, especially for tracking shots where the camera is moved to follow the subject. The camera dolly is typically pushed or driven with the camera dolly wheels rolling on the ground. However, when filming on outdoor sets such as grass, snow, beaches or other uneven surfaces, dolly track is used. Dolly track generally has two tubular parallel rail sections joined by spreaders or ties, similar to railroad track. The wheels of the camera dolly are adapted to fit onto the rails.
The track is provide in straight and curved sections of varying lengths, with the sections joined together to provide the desired track route. The track provides a uniform and rigid surface for the dolly to allow for smooth filming. With some types of track, the rails are pivotally attached to the spreaders, to allow the track sections to fold inwardly for storage or transport. Although various forms of camera dolly track have been used, improvements are needed to provide better performance and versatility.